1. Field of the Invention
This invention relates to an endoscope or instrument which is utilized for performing procedures in a cavity and more particularly is directed to an endoscope, which in the preferred embodiment is a laparoscope having a distal tip which includes a distal optical lens and a means for utilizing a selected portion of a fiber optic light carrying bundle which passes light energy having infrared radiation. The laparoscope has a selected number of the optical fibers treated in a manner to use the same as a distal lens heating means to resist fogging of the distal lens when the distal tip of the endoscope is inserted into a warm, moist cavity, such as, for example, a body cavity. In addition, the laparoscope can include means including a fluid channel for defining a nozzle at the distal tip which is capable of directing a fluid flow across the distal lens to keep the exterior surface free from image impeding material. Additional channels, including an accessory channel, can be provided in the laparoscope to provide a stream of irrigation fluid, for applying suction to a working site or for the passage of working accessories such as laser fibers, electrosurgical probes, bi-polar probes and the like.
2. Description of the Prior Art
An endoscope is an instrument for examining the interior of a hollow cavity. Typically, an endoscope includes an optical system having a transparent member located at the distal end for passing an image. The transparent member may be a distal lens. Endoscopes are used in medical surgery and for other applications, such as, for example, inspecting the interior of a jet engine. In the medical field, one class of endoscopes are known as laparoscopes. The preferred embodiment of this invention is utilized in a laparoscope. The use of laparoscopes for performing laparoscopic procedures is well known in the art. A laparoscope is one class of an endoscope. Endoscopes are used for performing medical surgical procedures. Typically, the state-of-the-art laparoscope includes a rigid elongated sheath tube which encloses a image transferring means channel which receives a fiber optic image light bundle or relay lens system. A distal lens is typically used at the distal tip of the laparoscope to pass an image to the image transferring means. The image transferring means channel is typically surrounded by fiber optic light carrying means. The distal end of the laparoscope is used to develop an optical image of an operating site within a cavity and the operating site is illuminated by light from the fiber optic light carrying means. The optical image is transmitted through the distal lens and the image transferring means to the proximal end of the laparoscope where a viewable image is observed by the surgeon. The state-of-the-art laparoscopes are usually inserted through a cannula and trocar assembly which makes an incision or opening in the navel or belly-button of a patient. The purpose of making the incision in the navel or belly-button is to minimize the size of the surgical scar which remains upon completion of the surgical procedure. It is also known in the art to utilize a primary cannula and trocar assembly to form the initial opening through the navel or belly-button into the abdomen or the peritoneal cavity and use smaller cannula and trocar assemblies which are inserted into other smaller incisions to provide access to the peritoneal cavity for passing working tools. In the known laparoscopic procedures, the peritoneal cavity is insufflated with an appropriate fluid such as carbon dioxide (CO.sub.2) gas, concomitant with laparoscopic or peritoneoscopic examination, diagnosis and/or treatment, including the excision of structures and tissues in the peritoneal cavity. In the recent past, the type of surgeries performed using laparoscopic procedures has been expanded into new minimum invasive surgical procedures. One such new procedure utilizes the laparoscope, with other appropriate instruments, for performing laparoscopic cholecystectomy which is essentially a minimum invasive surgical method for removal of a gallbladder. Similar minimum invasive surgical techniques are being developed using laparoscopes to remove other organs, such as the appendix, kidney or tissues, such as from the liver, also located in the peritoneal cavity. Also, laparoscopes are used in thoracoscopy and gynecology.
In the laparoscopic cholecystectomy procedure, the laparoscope is utilized to provide the surgeon with a video image of the operating site. The video image is provided on a color television monitor and that image is used by the surgeon to perform the procedure. To obtain the optical image, a small high sensitivity video camera is usually operatively attached to the eyepiece of the laparoscope. The surgeon is able to insert and manipulate other instruments through auxiliary cannula and trocar assemblies located at small punctures made in the abdomen, all under the view of the surgeon through the video image developed by the video camera.
As part of the laparoscopic cholecystectomy, instruments are utilized through the various small openings to place a traction on the diseased organ. Under observation of the laparoscope, the surgeon attaches clips to the arteries and ducts leading to the gallbladder and then performs an incision between the clips. By using such techniques, the gallbladder is ultimately dis-attached from the liver. Once the gallbladder has been separated from the liver, the gallbladder can then be pulled through one of the small tiny holes. The patient usually goes home the next day with usually three or four punctures which will form small scars.
The laparoscopic cholecystectomy using a laparoscope is one of the minimum invasive surgical techniques that is expected to be expanded in the future to include other surgical procedures to be performed in the peritoneal cavity, chest cavity and other cavities within the body.
It is known that when the distal tip of the laparoscope is inserted into the peritoneal cavity, a fogging or condensation occurs across the distal tip which impedes the passage of the optical image and which interferes with the ability of the surgeon to view the operating site. This fogging condition or condensation buildup is due to the fact that the operating room temperature is in the order of 20.degree. C. (68.degree. F.). However, the interior of the peritoneal cavity or abdomen is generally at blood temperature which is typically in the order of 37.degree. C. (98.6.degree. F.). Thus, when a laparoscope, which is maintained at room temperature in the operating room which is typically 20.degree. C. has the distal tip thereof at room temperature of about 20.degree. C. inserted into the abdomen having a temperature of approximately 37.degree. C., the temperature differential therebetween is sufficient to cause instant fogging of the distal lens.
One known method for solving this problem art, is to heat the distal tip of the laparoscope by a variety of means. One heating method that is utilized to heat the distal tip is to insert the distal tip into a container of hot water to raise the temperature of the distal tip to approximately 37.degree. C. Another known technique is to place the distal tip in hot towels for a sufficient period of time to raise the temperature thereof to approximately 37.degree. C. It is desirable to keep the temperature below 42.degree. C .because tissue damage can occur at around 42.degree. C. Therefore, the preferred temperature is about 37.degree. C. to avoid the possibility of the distal end damaging tissue.
Another known method for solving this problem is to use a prewarmer cap which absorbs and reflects thermal energy passed by a fiber optic light guide bundle (sometimes known as a fiber optic light carrying bundle) through an endoscope distal end to raise the temperature thereof to a level which resists fogging of the distal lens when the distal end of the laparoscope is inserted into a body cavity. The prewarmer cap is removed just before the surgical procedure begins.
Such device referred to as a Laproheater Cap is offered for sale and sold by CIRCON ACMI, located in Stamford, Conn., as Catalog No. LAPHCP.
In addition to the above fogging problem, other image impeding problems are encountered during a procedure. When a surgeon is performing a procedure, that procedure normally results in particulate matter such as protein, blood, tissue and the like, being splattered throughout the operating site during the procedure. Typically, certain of the particulate matter will adhere to the distal surface and transparent member or distal lens located at the distal tip of the laparoscope thereby impeding the transmission or passage of the optical image through the transparent member or distal lens. This is particularly true during use of laser and electrocautery procedures for removing tissue.
In a typical laparoscopic procedure, particulate matter accumulates on the distal end three or four times during a procedure. Each time the optical image is impeded by the accumulation of particulate matter, it is necessary for the surgeon to remove the laparoscope through the cannula and trocar assembly, to physically wipe the particulate matter off of the transparent member, located at the distal tip of the laparoscope, and then reinsert the laparoscope through the cannula and trocar assembly back into the abdominal or peritoneal cavity to continue the procedure.
It is also known in the art that when utilizing a laparoscope in a laparoscopic procedure, such as, for example, the laparoscopic cholecystectomy briefly described above, it is necessary that the distal lens be free from light impeding agents such as a layer of fog, protein material or organic material. It is the desire of the surgeon to keep the laparoscope in the peritoneal cavity at all times.
It is known in the field of endoscopy to utilize endoscopic instruments for performing endoscopic procedures in the upper gastrointestinal tract ("GI Tract"). In performing the endoscopic procedures in the upper GI Tract, the endoscopic procedures are generally performed using flexible instruments such as, for example, a TX-8 panendoscope (Esophago-gastro-duodenoscope) which is one of a family of panendoscopes and other gastro-intestinal endoscopes manufactured by ACMI, a predecessor to the Assignee of the present application.
The TX-8 panendoscope was designed to be used in endoscopy of the upper GI Tract. The TX-8 panendoscope was used primarily as a visualizing instrument and employing flexible optical fibers, both to transmit illumination to the operating site or area immediately in front of the endoscope and to transmit an optical image of that operating site or area from the distal tip to an eyepiece located at the proximal end of the TX-8 panendoscope. The optical image so generated by the TX-8 panendoscope was viewed by an operator or transmitted to a film or television media by means of a television camera.
In the TX-8 flexible panendoscope, vision or image impeding agents were removed from the front lens and the illumination ports by the use of air, water and suction. The air, water and suction functions were operated by finger controls located conveniently on the control head of the TX-8 panendoscope. The air input also acted as insufflation medium to improve visualization. The suction channel doubled as an end-to-end conduit through which a variety of diagnostic and therapeutic devices, such as forceps, cytology brushes, graspers and the like could be introduced into the field of view to be explored under vision control.
Another known device offered for sale and sold by the predecessor to the assignee of the present invention is a TX-6 Cannulator Duodenoscope which was utilized for endoscopic retrograde cholangio pancreatography. The TX-6 cannulator duodenoscope also included a means for removing image or vision impeding agents from the front lens and irrigation ports of the instrument.
U.S. Pat. No. 5,207,213 discloses a laparoscope having means for removing image impeding material from a distal lens.
It is also known in the art to utilize a suction-irrigation handle for endoscopic surgery of the paranasal sinuses and the anterior base of the skull. The suction irrigation handle for the endoscope is essentially a rigid sheath which receives a working telescope. The rigid sheath includes a single channel which was capable of being used for either irrigation or suction of the operative site in the paranasal sinuses or in the anterior base of the skull. The suction-irrigation handle was utilized by the surgeon to irrigate an operating site with an irrigation solution and then to remove the irrigation solution from the site.
Operating laparoscopes are also known in the art. Typically, the known operating laparoscope has a rigid elongated sheath with a rigid optical path having two prisms, a fiber optic light guide and an operating channel. The operating channel port located at the proximal end of the operating laparoscope is coaxial with the operating channel. The rigid optical path extends perpendicular (at about 90.degree. ) from the rigid elongated sheath at the proximal end and then through a 90.degree. bend which then extends the rigid optical path along an axis which is parallel to the axis of the rigid elongated shaft terminating in an eyepiece. Prisms are used at each 90.degree. bend of the optical path. The fiber optic light guide enters the rigid elongated sheath at the proximal end and extends from the proximal end to the distal end. The operating channel was used to pass a monopolar grasping device which was used to perform tubal ligation. Laparoscopes have been known in the art for more than ten years. The fogging of distal tip of laparoscopes has been known for a similar period of time. None of the known prior art discloses, teaches or suggests a solution to the defogging problem utilizing the fiber optic light carrying bundle as a means for raising the temperature of the distal lens in response to light energy having infrared radiation, from a light source, to a temperature level to resist fogging of the lens at the commencement of and/or during a surgical procedure including during the use of a lens washing feature when cooler irrigation fluid is applied to the distal lens for a short time duration.